Metal wires have long been used to provide electrical communication between remote electrical systems. For example, remote sensors can communicate with sensor interface systems via metal wires. Aircraft, for example, have many such sensors and sensor interface systems, which have communicated with one another over metal wires. Such systems in the past have been shielded by the wings and fuselages, which had been constructed from metals, such as, for example aluminum. The fuselages, and/or wings of some aircraft are now being constructed using materials that are not conductive, such as, for example carbon composite materials. One consequence of using such construction materials is that electrical wires no longer are shielded by such materials.
For such wing constructions, lightning strikes can deleteriously interact with un-shielded electrically-wired systems. Wires for power or data transmission can induce an electrical discharge which can have undesirable consequences, especially in locations where such discharges can ignite a flammable liquid, such as aircraft stored in fuel tanks. Aircraft designers have begun replacing some electrical communications with optical communications. Thus, metal wires have been replaced by optical fibers. Optical communications still present potential problems. For example, the optical energy still must be controlled, because intense optical energy can still present ignition sources to flammable materials. Such dangerous conditions can arise, for example, if an optical fiber is severed within a fuel tank.
Thus, there is a need to control the energy of the optical signals guided by optical fibers.